Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.3 4.3bsd-beta 6/6/85; site decwrl.DEC.COM
Path: utzoo!watmath!clyde!burl!ulysses!bellcore!decvax!decwrl!dec-rhea!dec-star!fisher
From: fisher@star.DEC (Burns Fisher ZKO1-1/D42 DTN 381-1466)
Newsgroups: net.space
Subject: Capacitors to ignite model rockets
Message-ID: <600@decwrl.DEC.COM>
Date: Tue, 21-Jan-86 09:09:29 EST
Article-I.D.: decwrl.600
Posted: Tue Jan 21 09:09:29 1986
Date-Received: Thu, 23-Jan-86 20:54:55 EST
Sender: daemon@decwrl.DEC.COM
Organization: Digital Equipment Corporation
Lines: 33

>> >Sorry, computer grade capacitors aren't of any use for
>> >building railguns.  They have too much internal inductance
>> >to supply the sort of short, high-current pulse that you
>> >would need.  They won't even explode wires!  You might
>> >have better luck with photo-flash capacitors charged to
>> >an appropriately high voltage...
>> 
>> Rats!
> 
>Are you sure about this?  Just how short a pulse is needed, anyway?
>I used 'computer grade' capacitors of about 20,000 mfd charged
>to 20v or so to launch model rockets (circa 1972).  They did
>a dandy job of vaporizing the nichrom wire igniters!  (Though
>they did have enough charge left after the first launch to ignite
>one, and sometimes two, additional rockets).
> 
>It was my understanding that rail guns took a fractional second
>to a few seconds to accelerate something depending on design.
>Surely a model could be built that would be able to use computer
>grade caps?
>-- 
>E. Michael Smith  ...!{hplabs,ihnp4,amd,nsc}!amdahl!ems
> 
>This is the obligatory disclaimer of everything.

Sorry, E. Michael, I don't think that proves much.  I used flashlight
batteries (or at most, a lantern battery), and they gave the nichrome a
nice cherry glow!

Burns


...decwrl!rhea!star!fisher